Release 0.13.1

Added

• Dict schema support — Modules can now define input_schema / output_schema as plain JSON Schema dicts instead of Pydantic model classes. A _DictSchemaAdapter transparently wraps dict schemas at registration time so all internal code paths (executor, schema exporter, get_definition) work without changes.

Fixed

• get_definition() crash on dict schemas — Previously called .model_json_schema() on dict objects, causing AttributeError
• Executor crash on dict schemas — call(), call_async(), and stream() all called .model_validate() on dict objects

Improved

• File header docstrings — Enhanced docstrings for errors.py, executor.py, and version.py

---